Gaseous electric discharge device



Sept. 27; I932. M. PlRANl ET AL GASEOUS ELECTRIC DISCHARGE DEVICEOriginal Filed Aug. 19 1929 THEIR A TTORNE y 1 umn would break in inghollow body,

' ing point, since Patented Sept. 27, 1932 UNITED STATES PATENT OFFICEmARcELLo PIRANI, or IBERLIN-WILMERSDOR F HANS nwus'r, or IBERLI-N, AnnALFRED RUTTENAUER, or BERLIN-CHARLOTTENBURG, GERMANY, ASSIGNOBS T0GENERAL ELECTRIC comu NY, .A CORPORATION or N W YORK GASEOUS ELECTRICDISCHARGE DEVICE Application filed August 19,1929, Serial No. 387,057,

and in Germany August 21, 1928. Renewed January 29, 1931.

The present invention relates to electric discharge devices useful inthe arts generally, and' particularly as electric lamps.

eretofore, in electric discharge lamps with gas or vapor filling andwith a view to obtaining a steady urning, or to obtaining another lightcolor, and preferably a white light color, of the gasor vapor discharge,it has been proposed, among other things, to mount in the interior ofthe lamp chamber for the guidance of the gas or vapor dis charge, atubular body of insulating material, such as refractory oxides, whichwas supposed to be raised to a red heat by the discharge and thus causethe desired light rad iation. The placing of such a guide tube lightemitter in the discharge path, howev er, has been found very inefficientas the guiding tube absorbs or shuts off all or most of the light fromthe gas or vapor discharge. Furthermore, because of the relatively smalldielectric strength of such material it is not possible to build up thecurrent density of the discharge high enough-to attain the desiredresults.

' The use of metallic, conducting, solid walled hollow bodies for thehitherto proposed insulating material making up the guiding hollow bodyhas hitherto never been tried, or the opinion was that the light colsucha current conductand also that the current conductor used would only bebrought to a red heat.

It has been discovered, however, that the foregoing opinion is notcorrect and that the positive column of the discharge, probably underthe influence of the wall charge, goes freely. through a currentconductor ticularly a metallic hollow body.

In the new devices hereinafter described and using a solid wall hollowbody-of current conducting, high melting point material in particular ametal having a high meltdielectric strength naturally does not come inquestion, increased current density and therewith increased lightdensity are obtained in the operation of the de b vice. Also anysuitable high melting point gaseous and parsolid walled hollow body, asit can easily be made of uniform thickness over its entire length, whilewith a hollow body consisting of insulating material the wall thicknessis not evenly uniform and it may be more or less porous. The greateruniformity and homogeneity of the new hollow body consisting of highmeltingpoint conducting material has not hitherto been. attained inprevious devices and perfect uniformity of surface brightness is nowattained for the first time and which is very essential for the use ofsuch'lamps as projection means and for crack illumination.

A more essential advantage, in particular a much smaller lightabsorption takes place, if the new conducting guiding hollow body isprovided with holes or perforatlons throughout its entire length. Such asievelike conducting hollow body allows not only a large part of thelight from the gas or vapor discharge to go out unhindered through theopenings, but also is itself charged w1th perfect uniformity in all itsparts by virtue of' its good conductivity when the lamp 1s tricallycharged mesh of the hollow body, it is probable that a space charge iscreated which prevents the transfer of the gas or vapor column throughthe openings of the hollow body, The gas or vapor discharge 1s thuspositively confined within the hollow body, and also in a narrow spacetherem. This, in connection with the high heat durability ofthe hollowbody, permits the current density of the discharge to be raised.

very high.-

Finally, as the perforated current conducting hollow body. by virtue ofits essentially I small radiating surface has only a small heatradiating loss, thus it follows that with an equivalent applied currentan extremely higher current density of the discharge is secured.

The new perforated and conducting hollow body can consist of thin metalplates with punched perforations or of crossed ands or wire, it canfurthermore be in the shape of cylinders or prisms. The openings or meshof the conducting hollow body must of a hollow bod in a tube shape madeof a provided with chambers of conducting ma,-

quartz,

mesh ofrmolyb enum or tungsten wire net or corresponding wire web, onlyabout 10% to 20% of the light of the gas or vapor column is hidden fromview and therefore a higher temperature equilibrium is very easilyproduced and maintained.

It has also been discovered now that if, in addition to the aforesaidarc confining tube of conducting material extending between theelectrodes, the discharge tube is further terial surrounding theelectrodes instead of ones made of insulating material and heretoforethought necessary in a discharge device of this type, that an electricfield is created around each electrode which, in the operation of thedevice, confines the discharge to the electrodes in exactly the samemanner that the discharge is confined within the hollow tubeextendingbetween the electrodes and, furthermore, results in reducing thepotential required to start the device into operation and permits of itsoperation on 110 or 220volts commercial circuits and at greater currentand light densities than, when insulating electrode chambers are used.

The present invention is illustrated in'the accompanying drawing inwhich Fig. 1 is a sectional elevation of a gaseous electric dischargedevice of our invention and. Fig. 2 is a similar view ofan alternativeembodimen'tl In the drawing, 1 is a' container of glass, or othersuitable material containing gases or vapors or mixtures thereof, suchgases being, for example, nitrogen, carbonic vacid gas, neon, helium,argon, mercury, etc.

Container 1 is provided with stems 3, 3 on which are mounted theelectrodes 8, 8 consisting wholly or in part of material having highelectron emissivity. The sealed in current leads 5 for the saidelectrodes 8. are arranged inside two concentric insulated tubes 24, 27which rest on the base 3 and support a plate 25 which, in turn, supportsthe electrode 8. Surrounding the electrodes 8 are two chambers 10, 10'of conducting material, such as metal, one end thereof 11' be ing sprungover the stem 3 by means of the split portion 31 and resting on ring 29on the stem 3. The other end of said chambers 10' have openings facingtoward the opposite electrode and a tube 16 oftungsten wire net,-

. or other suitable material, is attached to the ends 12, 12' of saidchambers 10' and support the said net 16 in its position surroundby theuseing the gaseous dischargepath between the electrodes. I I

When desired, pointed pins 30, 30 of con ducting material, metal, forexample, are mounted in the chambers 10 and having their-pointed endsextending into close proximity to the electrodes 8, 8 as shown in thedrawing and the number of such rods is optional.

It is, of course, understood that the member 16 may be made of othermaterial than tungsten and can consist of a web of nonconducting oxiderare earths, for example, thorium oxide, cerium oxide or scandium oxidewhich is made conductive by the im-' pregna-tion of molybdenum or othersuitable conducting material.

In operation, the use of a sievelike conducting body surrounding the gasor vapor pathpermits the major part of the light from the gas or vapordischarge to pass unhindered through the openings and is itself chargedwith perfect uniformity inall its parts by virtue of its goodconductivity, when the lamp is put into operation. \Vith reference tothe electrically charged mesh 16 it is probable that a space charge iscreated which prevents the transfer of the discharge through theopenings of the enclosing tube.

The metal enclosing chambers 10 like the member 16 are electricallycharged and form an electric field around each electrode which, in theoperation of the device, confines the discharge to the electrodes inexactly the same Way that the gas or vapor discharge is confined Withinthe web 16.

The device above described, is found to be operable at high currentdensities wherein the tungsten wire network 16 is heated to an intensewhite heat, the radiations from the tungsten or other conducting bodybeing added to those of the as or vapor discharge and the device thereore can be used as a lamp for illumination or as a generator ofultraviolet or other rays by using a material permeable to the rays,visible or invisible, generated within the device.

An advantageous feature attendant upon the use of chambers of conductingmaterial about the electrodes and the conducting web 16' about thecurrent path is that the starting resistance of the tube, shown in thedrawing, is materially reduced and it is now possible to start andoperate such gaseous electric discharge devices with a light column ofabout 0.50 m. in length on commercial c1rcu1ts of Ill 110 or 220 voltswithout the use of high current starting impulses and consequentlywithout the use of transformers for generatrents of the greatestdensityare desired as is the case when using the new. lam

ps' as beacons. -In thls figure,

a tube seal structure is shown having a large current carrying which isscrewed into capacity in which the cap 32 of conducting material ishermetically sealed into the end of the container wall 1 and theelectrode 8 is mounted on the inner end of the rod 33 the top ofthe cap32. A supporting member 35 rests on the inner side of the cap 32 and isheld in place thereon by a nut 34 on the ,rod 33, the support member 35serving to hold the chamber member 11' in place. Tlfe rods 13, 13, ifdesired,may be used to aid in supporting the chambers 10, 10. Y

We claim:

- 1. In an electric discharge device, a container, electrodes sealedtherein, a gaseous filling therein, a tubularbody of conducting materialsurrounding the discharge path between the electrodes, and chambers ofconducting material surrounding said electrodes.

2. In an electric discharge device, a container, electrodes sealedtherein, a gaseous ling therein, a perforate tubular body of conductingmaterial surrounding the dis-- charge path between the electrodes, andchambers of conducting material surrounding said electrodes.

3. In anelectric discharge device, a con.- tainer, electrodes sealedtherein, a gaseous filling therein, a tubular body of conductingmaterial surrounding the discharge path be tween the'eleetrodes, andchambers of conducting material surrounding said electrodes, saidtubular body consisting of wire mesh.

4. In an electric discharge device, 'c0ntainer, electrodes sealedtherein, agaseous filling therein, a tubular body of conducting materialsurrounding the discharge path between the electrodes, and chambers ofconducting material surrounding said electrodes,

said-tubular body consisting of wire mesh comprising non-conducting andconducting materials. v r

5. In an electric discharge device, a container, electrodes sealedtherein, a gaseous filling therein, a tubular body of conductingmaterial surrounding the discharge path between the electrodes andpointed pins mounted on-said disc arge surrounding members and extendingtoward said-electrodes.

trodes to a value such that'the voltage of the 110 volt commercialcircuit on which said lamp is designed to operate is sutficient toinitiate the desired operation of the lamp. 7. A positive-columnelectric lamp comprising a container, electrodes sealed therein and agaseous atmosphere therein, the electro-motive force on which said lampis to operate being of .a value insuflicient to overcome the resistanceto startingexisting at said electrodes and in said discharge column, andan oelement of conducting material within said container surroundingsaid electrodes and the discharge path between them for reducing theresistance to current flow between said electrodes to a value such thatthe voltage of the current on which said lamp is designed to operate issufiicient to initiate the desiredoperation of the lamp.

8. A positive'eolumn electric lamp comprising a container, electrodessealed therein, a gaseous atmosphere therein, and an element ofconducting material surrounding each of said electrodes and the positivecolumn discharge path between said electrodes and out of contact withsaid electrodes for reducing the'resistance to current flow between saidelectrodes to a value such that the voltage of the current on which saidlamp is designed to operate is suflicient to initiate the desiredoperation of the lamp.

9. A positive column electric lamp comprising a container, electrodessealed therein, a gaseous atmosphere therein,'and an element ofconducting material extending from electrode to electrode and along thepositive column discharge path between said electrodes andout of contactwith-said electrodes for reducing the resistance to current flow betweensaid electrodes to a value such that "the voltage of the current onwhich said lamp is designed to operate is sufiicient to initiate thedesired'operation of the lamp.

In witness whereof we have hereunto set our hands this 5th day ofAugust, 1929.

MARCELLO PIRANI. HANS EWEST. ALFRED RUTTENAUER.

6. A positive column electric dischargelamp adapted to operateon 110voltcommercial circuits comprising a container, electrodes sealed thereinand a gaseous atmosphere therein, the electro-motl've force on whichsaid lamp is tooperate being of a value insuflicient to overcomestarting existing at said said discharge column, and an element ofconducting material within said container surrounding said electrodesand the disthe resistance to charge path between them for reducing theresistance to current flow between said elec electrodes and in

